Transformer



; Nav. 13, 1928,

mRANsronsR-v.

A Filed Apriljll, 1.925

INVENTOR.

Nov. 13, 192s.

1,691,125 w. J. POLYDoRoFr-f TRANSFORMER Filed April 11, 1925 s sheets-sheet 2 INVENTOR A TTORNE Y.

Nav. 13, 1928. 1,691,125 W. J. POLYDOROF F TRANSFORKER K Filed April 1l, 1925 3' Sheets-.Sheet 3 ATTORNEY.

Patented Nov. 13, 192s.

UNITED STATES PATENT OFFICE.

WLADIMIB J. POLDOROFF, OFOIIIOAGO, ILLINOIS, AssIGNoR To JOHNSON-WILLIAM- son LABORATORIES, INC., or CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

y TRANSFORMER.

Application ii'iea April 11, 1925. seriai No. 22,291.

.The invention relates tO transformers in general, and is especially adapted to high oi' radio frequency work It is common knowledge that one of thc difficulties experienced in present-day high-4 frequency apparatus, such as oscilla-tors and radio-receiving and transmitting sets, is-i'a.- diant electro-magnetic energy effects. The

present invention has for its object a deviceA ergy is not instantaneous throughout the en-A tire winding, but progresses through each successive tuin until the current and the consequent magnetic fie-ld have reached their maximum values throughout the coil. This is due, of course, to the fact that the current has to overcome the impedance Of the coil. In order to counterbalance this energy thus radiated by a coil, I have devised a means for establishing equal and Opposite fields associated with each successive turn, so that the radiant energy manifests itself as external fields of equal magnitudes and of opposite polarities which tend to counterbalance each other, to thereby minimize interference with adjacent circuits. Likewise, energy radiated from some external sourcewill not materially affect the transformer because it is so wound that' currents of opposite direction are established and neutralize each other. The invention will be better understood if reference is had to the accompanying drawing forming part of this speci fication, and in which- Figure 1 shows the winding of the transformer'; I Figure 2 shows the transformer provided with aniiron or a non-magnetic core; y

Figure 3 is a schematic view -Of the windings of the transformer;

Figure 4 shows a modification havingalternating primary and secondary windings; Figure 5 shows the transformer provided with an adjustable element, and associated with a variable condenser;

Figure 6 shows modifications of the transformer windings;

Figure 7 shows Ordinary radio-frequency circuits, and a telephone circuit which is of audio frequency;

F .igure 8 shows annppaiatus having both radio-frequency and audio-frequency circuits, and terminating in a telep-lionic circuit.

In all of the figures of the drawing, 1 and 2 are terminals of the primary winding 3, and 4 and 5 are terinnals ofthe secondary winding 6.

The primary and the secondary windings are similar, both of said windings, as shown, having continuous and reversed half-turns simulating the figure 8. When acurrent of electricity is passed` through the windings, two magnetic fields are set up with unlike poles each end.- This forms a complete magnetic circuit of flux within the trans former. Progressively from turn to turn a field is set up in one half turn, followed by a sep-arate field in the other half turn, until the field is established throughout the entire transformer. The aforesaid half turns produce what may be regarded as solenoidal elements with their windings in series, although other than serial windings may be employed provided the polarities are such that a complete magnetic circuit, such as described, is established.l

As shown in Figure 1, the windings are self-sustaining, but said windings may be disposed on iron or on non-magnetic cores 9, as

l shown in Figure 2.

'Figure 3 shows the primary and the secondary windings separated.

Figure 4 shows extensions 10 and 11 of the primary 3 and tlie secondary 6, respectively. Figure 5 shows a rotary extension l2 of the primary having an actuating element13-on its shaft 13, which shaft extends through the hollow shaft 13b of a condenser 13c having a knob 13d. Said' knob and said actuating element 18 may be operated simultaneously or separately in order to secure the desired ad]ustments of the primary coil, the secondary coil and the condenser. Reversal Aof the rotary extension 12 operates to reduce transformation from maximum to minimum.

The coils may be of various forms as shown in Figure 6, but, in all cases,the wires should be laid in parallel if maximum transforma.-

tion is desired. aA represents a winding having four partial turns, while b represents a winding of, polygonal form.

- and the battery polarities,

Figure 7 shows the new transformer applied to a radio apparatus. 14 is the antenna, and Sthe primary winding of the first transformer 15, 6 being the secondary winding. Additional transformers 16, 17, in series with the grids 17a, may be employed, and these additional transformers may be of t-he type shown in Figure Ll.

Figure 8 shows a network similar to that revealed in Figure 7, there being, however, stages of audio frequency 16a and 17a. In Figure 7 the arrow a: indicates that the transformer and the condenser of t-he second radio stage are simultaneously adjustable, and the arrow y in Figure 8 shows that the corresponding elements in the detector grid circuit are simultaneously adjustable.

The set includes a plurality of radio-frequency amplifying tubes 18, and variable condensers 19 shunted across the filamentgrid circuits as shown in Figure 7. The third tube 18a is a detector tube. Batteries 2O supply current to each of the filaments of said amplifying tubes, and the detector tube, 21 supplies current to the telephonie circuits which 'include the plates 22, the primaries of the second and third condensers, and the telephone 23. This description applies to the corresponding elements of Figure 8.

A transformer of the type herein set forth may be wound in such a way that both primary and secondary coils will be very close together, and such a transformer is very useful as an interstage coupling between threeelectrode tubes operating as radio or highfrequency amplifiers in a radio receiving apparatus. 4

Every half turn of the transformer forms substantially a circle with a magnetic field of the same strength as the adjacent'half turn, so that both vof these half turns build up a magnetic field passing through the coils, thus closing itself with a minimum number of lines of force outside and a maximum number of lines of force inside said coils. I

The primary and secondary windings of the transformer, being inclose magnetic relation, insure agood transformation of energy from the primary to the secondary circuit, without -radiation of material energy to the adjacent coil or to the wires of the receiving circuit. It appears to be the fact that the external lines of force developedby the half turn of the transformer are of opposite and that, for this reason, they substantially neutralize each other and cannot,

therefore, induce currents in extraneous or adjacent circuits. The c lose coupling between the primary and the secondary admits of a small number of turns inthe primary winding, so-that the natural period of said primary winding is considerably lower than that of the secondary winding.

wound in such a way The transformer has a low distributed capacity and a low natural period as compared with a single-la ersolenoid.

Having thus escribed my invention, I claim is:

1. An electrical device including a radio what l frequency transformer having a plurality of v separate windings,

said windings being in close magnetic relation, a magnetic field of a primary windingibeing substantially enclosed in other windings, and said windings being wound in such a way that every half turn forms a complete circle and i`s continued in the sal'ne plane and same form, but in a direction opposite to another half winding.

'2. A radio frequency coupling transformer having a plurality of separate windings, said windings being closely wound in such manner that to each half turn of said winding another half turn of same shape and area is continually added, wound in reverse direction; the said windings being placed in sections so that a primary winding is substantially in the center, whereby a magnetic field is enclosed within the transformer.

3. A radio frequency transformerhaving a plurality of inductively related windings that every half turn completes a circle, producing a definite magnetic polarity when current flows, and to said half turn another half turn in the form of a similar circle is added in reversed direction, whereby equal and oppositefield polarities are produced in primaryturns and induced upon an adjacent secondary turn wound in the same way as said primary turn.

4. A radio-frequency transformer having primary and secondary windings so wound that the halves of complete turns are of the same slape and area, both halves are in the same plane, magnetic lines of force produced by current flow in the turns are equal and dpposite, and the resultant field of the turns tends to 'close itself withinsaid turns and within an adjacent secondary turn.

5. A radio-frequency transformer having two or more continuous windings, alternatively wound in sections of primary and secondary windings, every turn of said winding being placed in halves wound symmetrically and in different directions, thereby producing a magnetic field which tends to close itself within said windings.

6. A transformer having a primary and a secondary winding, the turns of said windings being arranged in groups, and each of said windings having a plurality o'f reversed half turnsthrough which currents may iow in opposite directions to thereby establishA av contmuousflux circuit within said half turns.

7. A radio-frequency transformer having' and so wound that to every half turn of the winding a symmetrical and oppositely wound half turn is added so that outside electric disturbances are equally and oppositely induced upon two halves of every turn, whereby said electric disturbances are neutralized inside of the transformer.

8. A radio-frequency transformer having primary and secondary sectional windings laid in such a way that primary sectional windings are wound with relation to the secondary sectional winding, every section being wound to produce two equal and opposite magnetic fields, the said fields being substantially a continuation of one another.

9. A radio-frequency transformer having ltwo solenoidal windings, these solenoidal windings being laid alternatively on two cyylindrical forms so that to every half turn of the windings a symmetrical and oppositehalf turn is added, the primary winding being in the middle portion of said forms, and the secondary winding being at the ends of said forms, whereby the primary magnetic field is substantially enclosed in the secondary winding. y v t 10. A radio-frequency transformer having sectional primary and secondary windings wound in the shape of a double solenoid with every turn of the winding spread over two cylindrical forms, so that half turns complete circles around the cylindrical forms, but in opposite directions so that an inlinite number of points of each half turn of the transformer will produce magnetic fields equal and opposite at the same points on the other half turn, the magnetic field of primary winding being substantially enclosed in secondary turns.

11. A transformer having in combination windings in reversed half turns arranged alternately in adjacent groups, the conductors crossing at single points and operatively connecting alternate half turns.

12. A transformer having a primary and secondary winding each laid in reversed halfturns which together simulate the'igure 8.

13. A transformer including continuous windings wound so that half turns are arranged side by side successively reversed and conductively connected one with another.

14. An electrical device including a transformer with plurality of windings wound so that half turns are arranged side by side and are successively and conduc-tively connected one with another, and that a stronglclosed internal field and two equal and opposite and external fields are produced when a current progresses through said windings.

15. A radio-frequency transformer having an input, and a winding leading from said input and constituting a reversed half-turn, said Winding leading from said half-turn and forming another reversed half-turn disposed in substantially the same plane as said firstnamed turn, the winding being continued in the same manner throughout the transformer.

In testimony whereof I alx my signature.

WLADIMIR J. POLYDOROFF. 

